metamorphic

Iron-rich sulfide-bearing metamorphic rock

Likely pyrite- and/or chalcopyrite-bearing schist; identification is uncertain from imagery alone

AI-generated identification · may be incorrect

Dark brown-black, strongly metallic to submetallic glitter, with brassy yellow sulfide grains and rusty oxidation. Likely hardness around 3–6 depending on sulfide content; irregular fracture and weak foliation are visible, with no reliable cleavage or specific gravity measurable from the image.

Identified September 19, 2026More metamorphic →

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Physical properties

Formation & geological history

Probably formed when sulfide-rich sediment or hydrothermal mineralization was metamorphosed, then weathered near the surface; age depends on its geological setting. Oxidation of iron sulfides produces the orange-brown limonite/iron-oxide coating.

Uses & applications

Primarily a mineral-collecting specimen; sulfide ores can be sources of copper, iron, and sulfur, but this small piece has no evident commercial value. It is not typically used as a construction stone or gemstone.

Geological facts

Brassy grains may be pyrite (FeS₂), chalcopyrite (CuFeS₂), or both; chalcopyrite is softer and commonly tarnishes iridescently. A definitive identification requires streak, hardness, density, and ideally X-ray diffraction or chemical testing.

Field identification & locations

Look for brass-yellow metallic grains, dark foliated matrix, and rusty weathering; pyrite gives a dark greenish-black streak, whereas chalcopyrite commonly gives a greenish-black streak. Common settings include hydrothermal veins and metamorphosed massive-sulfide deposits.